492 F. ERNEST "WEISS. 



cited as wanting confirmation. I feel sure, however, that 

 much that is new might be made out by careful investigation 

 of Amphioxi fed with carmine as above described. 



The coelomic cavities were singularly free of carmine, so 

 that it would seem as if the vascular system were more dis- 

 tinctly separated from the coelomic system than has hitherto 

 been supposed. 



In the metapleural lymph-spaces, however, I constantly 

 came across cells containing carmine, though not to any very 

 considerable extent. 



My object, however, being to trace the carmine to the 

 excretory organs, I found it best to examine specimens in 

 which the carmine was already disappearing from the vascular 

 system. After a week or a fortnight Amphioxi kept in the 

 carmine-containing water would have assumed a quite definite 

 pink coloration, and I then transferred them into a tank Avith 

 running water, where they gradually became paler. Amphioxi 

 thus treated gave the best results for the purposes I had in 

 view. 



As already mentioned, the patches of modified epithelial 

 cells on the ventral wall of the atrium have a very definite 

 blood-supply, of the nature of a subepithelial blood-space with 

 short blood-vessels running up between the cells (fig. 6), and 

 when the vessels were well coloured I found also carmine 

 granules in these cells. In many cases they were not readily 

 distinguished on account of the deep-coloured granules con- 

 tained in the cells, and only in specimens which were very 

 slightly pigmented could these carmine granules be unmis- 

 takably seen. This pigmentation of the atrial epithelium pre- 

 vented my ascertaining whether excretion takes place to any 

 great extent over its entire surface, or whether it is confined 

 to the specialised portion described by Miiller. It was this 

 same circumstance which prevented me from obtaining any 

 positive results from examination of the atrio-coelomic funnels 

 described by Professor Lankester. They are applied, as shown 

 in Professor Lankester's drawings, to the wall of the dorso- 

 pharyngeal coelom, along which wall, as I have stated before, 



